2000 Dodge Grand Caravan horn not working. There isn't a dedicated fuse. What else can I do?

in the power distribution center on the left side of the engine compartment there is 20A fuse #7 which goes to the horn relay. Also, as an assistant pushes the horn, you should be able to feel the horn relay clicking if it's good.
If the fuse and relay are good check for voltage at the horns themselves when the horn "button" is pushed.

i'd start by checking for power at the horn, with the pad pressed, with just a common 12 volt test light. if it lights, it's a horn replacement and it's the most common problem. dayshifter's on target.

Do you also have indication that the air bag system is not working. If so, the problem is the clock spring in the under the stering wheel. This device serves to transfer power from the turning stering wheel to the steering column. It was a chrystler recal but you probably have too many miles on your van to qualify now. Google "Dodge clock spring", and you will get plenty of info on it. When I replaced mine it cost about $60.00. VERY VERY VERY IMPORTANT, disconnect the negative battery terminal before you work on any thing related to the stering wheel so that you don't have the air bag active and injure yourself.